Hoover Offshore Oil Pipeline System (HOOPS) GA-A244 · PDF fileThe Hoover Offshore Oil...

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Hoover Offshore Oil Pipeline System (HOOPS) GA-A244 Bypass and Wye Inspection

December 2017- MTS Houston Luncheon

The Hoover Offshore Oil Pipeline System (HOOPS) is

a 153 mile common carrier pipeline system that runs

from the Western Gulf of Mexico to Quintana Terminal

- south of Freeport, Texas. It transports crude oil from

a number of offshore production facilities, including:

Shell Perdido, ExxonMobil Hoover-Diana, Anadarko

Gunnison, Boomvang and Nansen to Seaway’s

facilities at Jones Creek and Texas City.

HOOPS was installed in 1999; is operated by EM

Pipeline Company (EMPCo) and has capacity of

100,000 bpd.

The HOOPS system includes:

• Mid point pumping platform at GA-A244 that was

tied in to HOOPS in 2002

• 73 mile pipeline from Hoover/ Diana Platform

upstream of GA-A244

• 81 miles pipeline to Quintana Station downstream

of GA-A244 platform

• 96 mile Alpine Pipeline from Gunnison tied into

GA-A244

• 57 mile BANJO pipeline ties into Boomvanng and

Nansen at GA-A244

• 70 mile Perdido export pipeline ties into a

deepwater subsea tie-in near Hoover

HOOPS Background

Hoover - Diana

Perdido

Gunnison

Boomvang

Nansen

GA-A244

Quintana Station

• Two pipeline dead legs exist near the GA-A244 platform

on the HOOPS pipeline. Dead Legs are sections of the

pipeline circuit that contain idle, stagnant or intermittently

flowing fluids. Since they are not in continuous services

they are particularly susceptible to corrosion and

degradation.

• The primary scope of work for this project was to

examine the pipe segments in the dead-leg zones for

internal wall loss that might have been caused by

microbial influenced corrosion (MIC), or any other local

internal corrosion mechanism.

• 12” bypass with isolation valve between upstream and

downstream segments

• 16” wye and valve on dead leg spool on upstream side of GA-

A244 platform.

• EMPCo risk assessment of bypass integrity assessed

dead legs as level II on risk matrix

• Concern on MIC exposure and deterioration of internal lining

• Bypass valve has not been opened in 15 years of operation

HOOPS Bypass Inspection - Background

Objectives • Perform external inspection to determine

level of corrosion present in the subsea dead legs in vicinity of GA-A244

• EMPCo work with EMPC and EMDC for inspection execution guidance.

• Leverage intercompany knowledge with application of subsea in-situ external corrosion inspection technologies and review of inspection data

• Leverage intercompany experience in planning offshore operations to safely access, inspect, and restore the subsea dead leg areas

HOOPS Pipeline Bypass Inspection

GA-A244

Platform

Dead-leg

Bypass

Dead-leg

Key Activities • Selection of appropriate technologies and contractors for

in-situ corrosion inspection • Contractor Selection – Commercial – Procurement • Contractor, vessel, dive system and crane assurance

inspections • Subcontracting to develop a site-specific kit for the NDT

inspection, including mock-up SIT. • Mobilization of the Dive Support Vessel to GA-A244. • Uncovering each dead leg and preparing the pipe

sections for inspection. • Performing the NDT inspections. • Re-installing grout/sandbags and mattresses to support

and protect each dead leg.

Site Preparation (1)

Purpose: Clear all cover / material from the areas around

the pipeline area, excavate clearance around dead legs,

and prepare for inspection.

Key Activities:

• Remove/ peel back concrete mattresses

• Break up/ excavate sand bags/ grout bags

• Dredge underneath dead legs

• Temporary supports or fixtures

High probability of concrete 3:1 bags and/or mattresses

placed beneath piping flanges & wishbone piggable wye

during installation.

Assume lifting points on mattresses and sand bags/grout

bags integrity has degraded over 12-15 years since

installation

Evaluate concerns to ROV operation over operating

pipeline with proximity to pipe versus controlled diver

operations. ROV only operation, including tooling, would

be estimated to take substantively longer and cost greater

than and combined ROV / Diving option.

Working areas

(notional)

Support may be required

Bypass dead leg:

• Limited access around left side of dead leg for currently

available tools (less than 3”)

• Individual tool access requirements and dead zone at ends

limit the range of coverage of an individual tool (varies

between (1-2 -in up to 1”)

• Preference for ring shaped tools to map either in

circumferential or axial directions with automated UT

corrosion mapping with high density on bottom quadrant

• Geometry is made of straight sections with interaction

around tees and valve mid way

• Subsea ball valve has not been stroked in recent history

(10+ years), weigh chance for success

• Actuation of subsea valve by ROV requires modifications

Corrosion Inspection and Valve Check (2)

Wye Dead leg:

• Two different diameters (20”, 16”) with a concentric reducer

• Nearly all of wye branch is composed of long radius induction

bend, ruling out application of long linear UT mapping tools

• Individual tool access requirements and dead zone at ends

could limit inspection of some tools in area adjacent to wye,

reducer, and valve flange

• Few self crawling elements are able navigate long radius

• Preference for UT corrosion mapping at high density of

measurements or multiple passes on bottom quadrant

Proposed

Inspection

Proposed

Inspection

GA-A244 EMPCo HOOPs Dead Leg Inspection

Planning Process

• Selection of appropriate technologies and contractors for in-situ corrosion

inspection

• Contractor Selection – Commercial – Procurement

• Contractor vetting, vessel, dive system and crane assurance

• Subcontracting of Sonomatic to develop a site-specific kit for the NDT

inspection, including mock-up SIT.

• Procedures development, risk assurance

ExxonMobil Diving Expectations & GP

ExxonMobil USM Chapter 27 ExxonMobil GP 30-04-01

Diving Industry Guidelines and Regulations

OGP Report No. 411

United States Coast

46 CFR Part 197,

Subpart B - "Commercial

Diving Operations."

Sonomatic AUT Mock-up and SIT

Dive Support Vessel Bibby Sapphire

Bibby Sapphire Saturation System Audit

Diver Hands-on Tool training

GA-A244 EMPCo HOOPs Dead Leg Inspection Results

GA-A244 EMPCo HOOPs Dead Leg Inspection Results Summary

GA-A244 EMPCo HOOPs Dead Leg Inspection Safety Results

Contractor – Aqueos Subsea, Bibby Subsea

Sub- Contractor – Sonomatic Inspection

Project Duration - 7 days of Execution, 5 days Decompression

38 - Saturation Bell Lock-outs – 345 feet of seawater

220 - hours of Diver Bottom Time

11,652 - Project man hours

0 - Safety or Environmental Incidents

US GoM Diving Safety Work Group 43

The US GoM Diving Safety Workgroup is a US GoM focused, non-competitive and non-commercial group of oil and gas operators, transmission companies, commercial diving companies, supporting sub-contractors, organizations and industry stake holders. The group will provide a unified voice to promote and improve diving safety, through the following:

• identification and sharing of best practices • identify and seek solutions to industry challenges and

issues • review and comment of existing and proposed standards

and guidelines • provide input to the regulators and industry associations

US GoM Diving Safety Workgroup Vision Statement

US GoM Diving Safety Work Group

About the DSWG

History- Concept discussed in 2011 First DSWG General meeting held in February 2012 By-Laws adopted in May 2012 DSWG website rolled out in January 2013 2012 Membership – 33 General Members

24 Affiliate Members

2017 Membership – 55 General Members 66 Affiliate Members

About the DSWG

Continual Interaction with Regulatory and Industry Groups • USCG (U.S. Coast Guard) • ADCI (Association of Diving Contractors International) • IMCA (International Marine Contractors Association) • IOGP (International Oil and Gas Producers) • OOC (Offshore Operators Committee) • API (American Petroleum Institute)

Recognized by these groups

Requested to comment on proposed rules, Recommended Practices, etc.

Representatives from some of these groups regularly attend our meetings

About the DSWG

Accomplishments Through group comments and vetting, provided input

into future USCG Commercial Diving Regulations Provided comments to IMCA on document revisions Provided comments and influence related to Diver

Certification Acknowledgment through face to face meetings

Developed Guidance documents Provided an Industry Forum for Incident, Safety, and

Information Shares (over 300 Incident Shares to date)

About the DSWG

Committees and Developed Documents Live boating Guidelines Underwater Burning Guidelines Underwater Lift-bag Guidelines Hyperbaric Evacuation System Planning Hand Jetting for Underwater Excavation Minimum Manning Levels Emergency Response and Procedures Company Representative Guidelines Recommended Emergency Drills

http://usgomdswg.com

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US GoM Diving Safety Work Group – UW Burning Committee Work Group 48